Refractory material



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Patented t. 26, 1929.

UNITED "STATES 1,703,662 PATENT... OFFICE.

JOSEPH G. DONALDSON AND HENRY IJ. COLES, OF HAMILTON, OHIO, ASSIGNORS TO GUARDIAN METALS COMPANY, or DELAWARE.

HAMILTON, OHIO, A. CORPORATION OF REFRACTORY MATERIAL.

No Drawing. Original application filed. November 17, 1922, Serial No. 601,616. Divided and this applicai tion filed February 4, 1926. Serial No. 86,035.

The subject matter of this invention was originally disclosed in the application for Letters Patent of Joseph G. Donaldson and Henry L. Coles, Serial No. 601,616, filed November 17, 1922, and entitled Metallic alloys and process of forming the same, and which is now divided from the divisional application of Joseph G. Donaldson and Henry L. Coles, 'Serial No. 2,864, filed January 16, 1925, and entitled Refractory material.

This invention relates to steel and other metals suitable for use in the safe and vault industry, particularly metals which will rc-' sist penetration by the drill or by the local application of heat (as by the blow torch) or both. In a previous applicatiori of Joseph G. Donaldson, Serial No. 478,220, filed June 17, 1921, entitled Metallic articles of manufacture and method of producing the same, there has been describedmetals contain ng "cores of highly refractory material, WlllCll cores are encompassed in metal and preferably alloyed or united thereto. In our present invention we describe an improved material-which may be utilized in the same way, i. e.. as a core encompassed in metal. We do 4 not, however, limit ourselves to the use of this material as a core as the same has many commercial uses outside of its use as a core material. a

-We have found that highly refractory materials can be formed by taking a high-melting point oxide-such as the oxide of zirconium-and binding this together with a suitable binder such as a high-melting .point silicate.

" such, we have obtained excellent results by adding to the zirconium oxide approximately 9 to 11% silicon dioxide. When these substances have been comminuted and thoroughly mixed, the silicon dioxide and zirconium dioxide form zirconium silicate which, being in contact with an excess of zirconium dioxide, forms mixed crystals with the same and acts as a binder for the entire mass. To

either ofthe above substances we have foundv Graphite 7 to 9 '7 Silicon dioxide (SiOgl 9 to 11 7; Zirconium dioxide (ZIO 80 to 82 It is our present belief that the silicon dioxide should not exceed 12% of the entire formula.

Ores containing zirconia or zirconium silicate not infrequently carry impurities of iron and titanium oxide. l/Ve have found that these materials are detrimental to the formula and that the best results are obtained when either of these impurities constitutes less than 1% of the formula. The addition of carbon to the formula adds very greatly to the resistance of the finished material. This 1:; doubtless brought about by the fact that the carbon forms metallic carbides which are present as crystals or in solid solution.

hen the material herein described is used as a core, it is given a suitable size and shape and combined with a suitable metal, such as steel, as by being encased Wholly or partially therein. The core is preferably placed in a mould, metal (such as steel) being poured around it, as described in our former application. Thereupon the core material and encompassing material are brought into permancnt union by the alloying action which takes place at and adjacent to the areas in contact. The mass so alloyed is more highly resistant to penetration either by the drill or by the torch than any other parts of the material not subject to such alloying action. In the matter. of attempt to penetrate by means of the localized application of high heat, an important factor is the capacity of the material to conduct the heat away from thepoint of attack, thereby, in effect, diminishing the available cutting or fusing power of the torch.

Refractory materials, of the type described, 7

are excellent non-conductors of heat when cold but become conductors of heat when raised to a high temperature and thus'serve to dissipate the heat.

Cores containing a large proportion of zirconia have been found to shrink considerably '10 courses or the material may be broken into any.

when the same are cooled. To overcome this objection, we frequently-break up the core after the first meltmgand'remelt same. The core form'edby this second fusion will be found to be practically free from shrinkage cracks and to be more coherent than those cores which have been fused only once. These cores can be put in in strata which may be continuous throughout the metal or they may be placed in blocks which are set in staggered desired size or the core may beformed by binding together with a suitable binder the y broken pieces, all as set forth in the previous 1 herein described, are intensely hard and imapplication. In any event, the cores, made as penetrable by the drill. They are also substantially immune from attack by the blow torch. Furthermore, the core material, being a non-conductor of electricity, it is impossible to penetrate the same by means of the local application of the electric arc.

We claim y 1; The process of producing a metallic ar-' ticle which consists in mixing zirconium dioxide and silicon dioxide, adding carbon thereto in the form of graphite in quantity greater than is absorbed by said mixture,

heating the, mixture to fusion, cooling, preheating,iand pouringmolten metal around said preheatedmaterial whereby a union is formed bet een' said fused material and said metal. V

2. The process of producing a'metallic article which consists in mixing zirconium dioxide and silicon dioxide, adding carbon thereto in the form of graphite in quantity greater than is absorbed by said mixture, heating the mixture to fusion, cooling, preheating the fused material to approximately 1000 C. and

pouring molten metal around said preheated material whereby a union is formed between said fused material and said metal.

3. The process of producing a metallic artie1e which consists in mixing zirconium dioxide and silicon dioxide, heating the mixture to fusion, adding graphite to said mixture when the fusion has been nearly accomplished, 6001- mg, preheating said fused material to a temperature less than would cause a molten .condition thereof, and pouring molten metal around said preheated material,v a

This specification signed this 27 day of January, 1926. I y

l JOSEPH Gr.DONALDSON. f HENRY L. COLES. 

